Recent tabulations of U.S. cancer incidence data for the period 1976-87 have revealed sharply rising rates for adenocarcinoma of the esophagus and gastric cardia. The increases among males during this period ranged from 4 to 10 percent per year outpacing rises in skin melanoma, non-Hodgkin lymphoma, and other cancers. In contrast, trends for squamous-cell carcinoma of the esophagus were, stable, and for adenocarcinoma of other parts of the stomach, decreasing. To date, there have been no analytic epidemiologic investigations carried out in the U.S. to address risk factors for adenocarcinomas of the esophagus and gastric cardia. A population-based case-control study within the state of Connecticut is thus proposed to ascertain dietary, lifestyle and other risk factors for adenocarcinoma of the esophagus and gastric cardia, and to compare these risk factors with those for other cancers of the esophagus and stomach. In total, about 175 newly-diagnosed cases of adenocarcinoma of the esophagus and gastric cardia will be identified by the Rapid Case Ascertainment System, which is ongoing within the Cancer Prevention Research Unit for Connecticut at Yale University. An approximately equal number of randomly selected population controls will be frequency matched to the cases according to categories of age and sex. Controls will be identified using random-digit dialing for those under 65 years of age, and randomly chosen from rosters provided by the Health Care Financing Administration for those 65 years and over. In addition, the Rapid Case Ascertainment System will be used to obtain for comparison to the cases, an age-sex frequency-matched sample of about 175 newly-diagnosed cases of squamous-cell carcinoma of the esophagus and adenocarcinoma of other parts of the stomach. All of the cases and controls will be interviewed in their homes by a trained interviewer using a standardized structured questionnaire, to ascertain dietary history, tobacco use, alcohol consumption, and various occupational exposures and predisposing medical conditions. Data processing and analysis will be performed at the Cancer Prevention Research Unit at Yale. Average daily consumption of a number of dietary nutrients will be calculated from the diet histories, and univariate and multivariate analyses will be used to estimate relative risks for comparison of the esophageal and gastric-cardia adenocarcinoma cases with the controls and with the other cancer cases. This project will serve as the Connecticut site of a coordinated multi-center study on the etiology of adenocarcinoma of the esophagus and gastric cardia.